1use crate::{Grammar, InjectionConfig, Language, LanguageRegistry};
   2use collections::HashMap;
   3use lazy_static::lazy_static;
   4use parking_lot::Mutex;
   5use std::{
   6    borrow::Cow,
   7    cell::RefCell,
   8    cmp::{Ordering, Reverse},
   9    collections::BinaryHeap,
  10    ops::{Deref, DerefMut, Range},
  11    sync::Arc,
  12};
  13use sum_tree::{Bias, SeekTarget, SumTree};
  14use text::{Anchor, BufferSnapshot, OffsetRangeExt, Point, Rope, ToOffset, ToPoint};
  15use tree_sitter::{
  16    Node, Parser, Query, QueryCapture, QueryCaptures, QueryCursor, QueryMatches, Tree,
  17};
  18
  19thread_local! {
  20    static PARSER: RefCell<Parser> = RefCell::new(Parser::new());
  21}
  22
  23lazy_static! {
  24    static ref QUERY_CURSORS: Mutex<Vec<QueryCursor>> = Default::default();
  25}
  26
  27#[derive(Default)]
  28pub struct SyntaxMap {
  29    parsed_version: clock::Global,
  30    interpolated_version: clock::Global,
  31    snapshot: SyntaxSnapshot,
  32    language_registry: Option<Arc<LanguageRegistry>>,
  33}
  34
  35#[derive(Clone, Default)]
  36pub struct SyntaxSnapshot {
  37    layers: SumTree<SyntaxLayer>,
  38}
  39
  40#[derive(Default)]
  41pub struct SyntaxMapCaptures<'a> {
  42    layers: Vec<SyntaxMapCapturesLayer<'a>>,
  43    active_layer_count: usize,
  44    grammars: Vec<&'a Grammar>,
  45}
  46
  47#[derive(Default)]
  48pub struct SyntaxMapMatches<'a> {
  49    layers: Vec<SyntaxMapMatchesLayer<'a>>,
  50    active_layer_count: usize,
  51    grammars: Vec<&'a Grammar>,
  52}
  53
  54#[derive(Debug)]
  55pub struct SyntaxMapCapture<'a> {
  56    pub depth: usize,
  57    pub node: Node<'a>,
  58    pub index: u32,
  59    pub grammar_index: usize,
  60}
  61
  62#[derive(Debug)]
  63pub struct SyntaxMapMatch<'a> {
  64    pub depth: usize,
  65    pub pattern_index: usize,
  66    pub captures: &'a [QueryCapture<'a>],
  67    pub grammar_index: usize,
  68}
  69
  70struct SyntaxMapCapturesLayer<'a> {
  71    depth: usize,
  72    captures: QueryCaptures<'a, 'a, TextProvider<'a>>,
  73    next_capture: Option<QueryCapture<'a>>,
  74    grammar_index: usize,
  75    _query_cursor: QueryCursorHandle,
  76}
  77
  78struct SyntaxMapMatchesLayer<'a> {
  79    depth: usize,
  80    next_pattern_index: usize,
  81    next_captures: Vec<QueryCapture<'a>>,
  82    has_next: bool,
  83    matches: QueryMatches<'a, 'a, TextProvider<'a>>,
  84    grammar_index: usize,
  85    _query_cursor: QueryCursorHandle,
  86}
  87
  88#[derive(Clone)]
  89struct SyntaxLayer {
  90    depth: usize,
  91    range: Range<Anchor>,
  92    tree: tree_sitter::Tree,
  93    language: Arc<Language>,
  94    combined: bool,
  95}
  96
  97#[derive(Debug)]
  98pub struct SyntaxLayerInfo<'a> {
  99    pub depth: usize,
 100    pub node: Node<'a>,
 101    pub language: &'a Arc<Language>,
 102}
 103
 104#[derive(Debug, Clone)]
 105struct SyntaxLayerSummary {
 106    min_depth: usize,
 107    max_depth: usize,
 108    range: Range<Anchor>,
 109    last_layer_range: Range<Anchor>,
 110    last_layer_language: Option<usize>,
 111}
 112
 113#[derive(Clone, Debug)]
 114struct SyntaxLayerPosition {
 115    depth: usize,
 116    range: Range<Anchor>,
 117    language: Option<usize>,
 118}
 119
 120#[derive(Clone, Debug)]
 121struct DepthAndMaxPosition(usize, Anchor);
 122
 123#[derive(Clone, Debug)]
 124struct SyntaxLayerPositionBeforeChange {
 125    position: SyntaxLayerPosition,
 126    change: DepthAndMaxPosition,
 127}
 128
 129struct ParseStep {
 130    depth: usize,
 131    language: Arc<Language>,
 132    range: Range<Anchor>,
 133    included_ranges: Vec<tree_sitter::Range>,
 134    mode: ParseMode,
 135}
 136
 137enum ParseMode {
 138    Single,
 139    Combined {
 140        parent_layer_range: Range<usize>,
 141        parent_layer_changed_ranges: Vec<Range<usize>>,
 142    },
 143}
 144
 145#[derive(Debug, PartialEq, Eq)]
 146struct ChangedRegion {
 147    depth: usize,
 148    range: Range<Anchor>,
 149}
 150
 151#[derive(Default)]
 152struct ChangeRegionSet(Vec<ChangedRegion>);
 153
 154struct TextProvider<'a>(&'a Rope);
 155
 156struct ByteChunks<'a>(text::Chunks<'a>);
 157
 158struct QueryCursorHandle(Option<QueryCursor>);
 159
 160impl SyntaxMap {
 161    pub fn new() -> Self {
 162        Self::default()
 163    }
 164
 165    pub fn set_language_registry(&mut self, registry: Arc<LanguageRegistry>) {
 166        self.language_registry = Some(registry);
 167    }
 168
 169    pub fn snapshot(&self) -> SyntaxSnapshot {
 170        self.snapshot.clone()
 171    }
 172
 173    pub fn language_registry(&self) -> Option<Arc<LanguageRegistry>> {
 174        self.language_registry.clone()
 175    }
 176
 177    pub fn parsed_version(&self) -> clock::Global {
 178        self.parsed_version.clone()
 179    }
 180
 181    pub fn interpolate(&mut self, text: &BufferSnapshot) {
 182        self.snapshot.interpolate(&self.interpolated_version, text);
 183        self.interpolated_version = text.version.clone();
 184    }
 185
 186    #[cfg(test)]
 187    pub fn reparse(&mut self, language: Arc<Language>, text: &BufferSnapshot) {
 188        self.snapshot.reparse(
 189            &self.parsed_version,
 190            text,
 191            self.language_registry.clone(),
 192            language,
 193        );
 194        self.parsed_version = text.version.clone();
 195        self.interpolated_version = text.version.clone();
 196    }
 197
 198    pub fn did_parse(&mut self, snapshot: SyntaxSnapshot, version: clock::Global) {
 199        self.interpolated_version = version.clone();
 200        self.parsed_version = version;
 201        self.snapshot = snapshot;
 202    }
 203
 204    pub fn clear(&mut self) {
 205        self.snapshot = SyntaxSnapshot::default();
 206    }
 207}
 208
 209impl SyntaxSnapshot {
 210    pub fn is_empty(&self) -> bool {
 211        self.layers.is_empty()
 212    }
 213
 214    pub fn interpolate(&mut self, from_version: &clock::Global, text: &BufferSnapshot) {
 215        let edits = text
 216            .anchored_edits_since::<(usize, Point)>(&from_version)
 217            .collect::<Vec<_>>();
 218        if edits.is_empty() {
 219            return;
 220        }
 221
 222        let mut layers = SumTree::new();
 223        let mut first_edit_ix_for_depth = 0;
 224        let mut prev_depth = 0;
 225        let mut cursor = self.layers.cursor::<SyntaxLayerSummary>();
 226        cursor.next(text);
 227
 228        'outer: loop {
 229            let depth = cursor.end(text).max_depth;
 230            if depth > prev_depth {
 231                first_edit_ix_for_depth = 0;
 232                prev_depth = depth;
 233            }
 234
 235            // Preserve any layers at this depth that precede the first edit.
 236            if let Some((_, edit_range)) = edits.get(first_edit_ix_for_depth) {
 237                let target = DepthAndMaxPosition(depth, edit_range.start);
 238                if target.cmp(&cursor.start(), text).is_gt() {
 239                    let slice = cursor.slice(&target, Bias::Left, text);
 240                    layers.push_tree(slice, text);
 241                }
 242            }
 243            // If this layer follows all of the edits, then preserve it and any
 244            // subsequent layers at this same depth.
 245            else if cursor.item().is_some() {
 246                let slice = cursor.slice(
 247                    &SyntaxLayerPosition {
 248                        depth: depth + 1,
 249                        range: Anchor::MIN..Anchor::MAX,
 250                        language: None,
 251                    },
 252                    Bias::Left,
 253                    text,
 254                );
 255                layers.push_tree(slice, text);
 256                continue;
 257            };
 258
 259            let layer = if let Some(layer) = cursor.item() {
 260                layer
 261            } else {
 262                break;
 263            };
 264            let (start_byte, start_point) = layer.range.start.summary::<(usize, Point)>(text);
 265
 266            // Ignore edits that end before the start of this layer, and don't consider them
 267            // for any subsequent layers at this same depth.
 268            loop {
 269                if let Some((_, edit_range)) = edits.get(first_edit_ix_for_depth) {
 270                    if edit_range.end.cmp(&layer.range.start, text).is_le() {
 271                        first_edit_ix_for_depth += 1;
 272                    } else {
 273                        break;
 274                    }
 275                } else {
 276                    continue 'outer;
 277                }
 278            }
 279
 280            let mut layer = layer.clone();
 281            for (edit, edit_range) in &edits[first_edit_ix_for_depth..] {
 282                // Ignore any edits that follow this layer.
 283                if edit_range.start.cmp(&layer.range.end, text).is_ge() {
 284                    break;
 285                }
 286
 287                // Apply any edits that intersect this layer to the layer's syntax tree.
 288                let tree_edit = if edit_range.start.cmp(&layer.range.start, text).is_ge() {
 289                    tree_sitter::InputEdit {
 290                        start_byte: edit.new.start.0 - start_byte,
 291                        old_end_byte: edit.new.start.0 - start_byte
 292                            + (edit.old.end.0 - edit.old.start.0),
 293                        new_end_byte: edit.new.end.0 - start_byte,
 294                        start_position: (edit.new.start.1 - start_point).to_ts_point(),
 295                        old_end_position: (edit.new.start.1 - start_point
 296                            + (edit.old.end.1 - edit.old.start.1))
 297                            .to_ts_point(),
 298                        new_end_position: (edit.new.end.1 - start_point).to_ts_point(),
 299                    }
 300                } else {
 301                    let node = layer.tree.root_node();
 302                    tree_sitter::InputEdit {
 303                        start_byte: 0,
 304                        old_end_byte: node.end_byte(),
 305                        new_end_byte: 0,
 306                        start_position: Default::default(),
 307                        old_end_position: node.end_position(),
 308                        new_end_position: Default::default(),
 309                    }
 310                };
 311
 312                layer.tree.edit(&tree_edit);
 313            }
 314
 315            debug_assert!(
 316                layer.tree.root_node().end_byte() <= text.len(),
 317                "tree's size {}, is larger than text size {}",
 318                layer.tree.root_node().end_byte(),
 319                text.len(),
 320            );
 321
 322            layers.push(layer, text);
 323            cursor.next(text);
 324        }
 325
 326        layers.push_tree(cursor.suffix(&text), &text);
 327        drop(cursor);
 328        self.layers = layers;
 329    }
 330
 331    pub fn reparse(
 332        &mut self,
 333        from_version: &clock::Global,
 334        text: &BufferSnapshot,
 335        registry: Option<Arc<LanguageRegistry>>,
 336        root_language: Arc<Language>,
 337    ) {
 338        let edits = text.edits_since::<usize>(from_version).collect::<Vec<_>>();
 339        let max_depth = self.layers.summary().max_depth;
 340        let mut cursor = self.layers.cursor::<SyntaxLayerSummary>();
 341        cursor.next(&text);
 342        let mut layers = SumTree::new();
 343
 344        let mut changed_regions = ChangeRegionSet::default();
 345        let mut queue = BinaryHeap::new();
 346        let mut combined_injection_ranges = HashMap::default();
 347        queue.push(ParseStep {
 348            depth: 0,
 349            language: root_language.clone(),
 350            included_ranges: vec![tree_sitter::Range {
 351                start_byte: 0,
 352                end_byte: text.len(),
 353                start_point: Point::zero().to_ts_point(),
 354                end_point: text.max_point().to_ts_point(),
 355            }],
 356            range: Anchor::MIN..Anchor::MAX,
 357            mode: ParseMode::Single,
 358        });
 359
 360        loop {
 361            let step = queue.pop();
 362            let target = if let Some(step) = &step {
 363                SyntaxLayerPosition {
 364                    depth: step.depth,
 365                    range: step.range.clone(),
 366                    language: step.language.id(),
 367                }
 368            } else {
 369                SyntaxLayerPosition {
 370                    depth: max_depth + 1,
 371                    range: Anchor::MAX..Anchor::MAX,
 372                    language: None,
 373                }
 374            };
 375
 376            let mut done = cursor.item().is_none();
 377            while !done && target.cmp(&cursor.end(text), &text).is_gt() {
 378                done = true;
 379
 380                let bounded_target = SyntaxLayerPositionBeforeChange {
 381                    position: target.clone(),
 382                    change: changed_regions.start_position(),
 383                };
 384                if bounded_target.cmp(&cursor.start(), &text).is_gt() {
 385                    let slice = cursor.slice(&bounded_target, Bias::Left, text);
 386                    if !slice.is_empty() {
 387                        layers.push_tree(slice, &text);
 388                        if changed_regions.prune(cursor.end(text), text) {
 389                            done = false;
 390                        }
 391                    }
 392                }
 393
 394                while target.cmp(&cursor.end(text), text).is_gt() {
 395                    let Some(layer) = cursor.item() else { break };
 396
 397                    if changed_regions.intersects(&layer, text) && !layer.combined {
 398                        changed_regions.insert(
 399                            ChangedRegion {
 400                                depth: layer.depth + 1,
 401                                range: layer.range.clone(),
 402                            },
 403                            text,
 404                        );
 405                    } else {
 406                        layers.push(layer.clone(), text);
 407                    }
 408
 409                    cursor.next(text);
 410                    if changed_regions.prune(cursor.end(text), text) {
 411                        done = false;
 412                    }
 413                }
 414            }
 415
 416            let Some(step) = step else { break };
 417            let (step_start_byte, step_start_point) =
 418                step.range.start.summary::<(usize, Point)>(text);
 419            let step_end_byte = step.range.end.to_offset(text);
 420            let Some(grammar) = step.language.grammar.as_deref() else { continue };
 421
 422            let mut old_layer = cursor.item();
 423            if let Some(layer) = old_layer {
 424                if layer.range.to_offset(text) == (step_start_byte..step_end_byte)
 425                    && layer.language.id() == step.language.id()
 426                {
 427                    cursor.next(&text);
 428                } else {
 429                    old_layer = None;
 430                }
 431            }
 432
 433            let combined = matches!(step.mode, ParseMode::Combined { .. });
 434            let mut included_ranges = step.included_ranges;
 435
 436            let tree;
 437            let changed_ranges;
 438            if let Some(old_layer) = old_layer {
 439                if let ParseMode::Combined {
 440                    parent_layer_changed_ranges,
 441                    ..
 442                } = step.mode
 443                {
 444                    included_ranges = splice_included_ranges(
 445                        old_layer.tree.included_ranges(),
 446                        &parent_layer_changed_ranges,
 447                        &included_ranges,
 448                    );
 449                }
 450
 451                tree = parse_text(
 452                    grammar,
 453                    text.as_rope(),
 454                    step_start_byte,
 455                    step_start_point,
 456                    included_ranges,
 457                    Some(old_layer.tree.clone()),
 458                );
 459                changed_ranges = join_ranges(
 460                    edits
 461                        .iter()
 462                        .map(|e| e.new.clone())
 463                        .filter(|range| range.start < step_end_byte && range.end > step_start_byte),
 464                    old_layer
 465                        .tree
 466                        .changed_ranges(&tree)
 467                        .map(|r| step_start_byte + r.start_byte..step_start_byte + r.end_byte),
 468                );
 469            } else {
 470                tree = parse_text(
 471                    grammar,
 472                    text.as_rope(),
 473                    step_start_byte,
 474                    step_start_point,
 475                    included_ranges,
 476                    None,
 477                );
 478                changed_ranges = vec![step_start_byte..step_end_byte];
 479            }
 480
 481            layers.push(
 482                SyntaxLayer {
 483                    depth: step.depth,
 484                    range: step.range,
 485                    tree: tree.clone(),
 486                    language: step.language.clone(),
 487                    combined,
 488                },
 489                &text,
 490            );
 491
 492            if let (Some((config, registry)), false) = (
 493                grammar.injection_config.as_ref().zip(registry.as_ref()),
 494                changed_ranges.is_empty(),
 495            ) {
 496                for range in &changed_ranges {
 497                    changed_regions.insert(
 498                        ChangedRegion {
 499                            depth: step.depth + 1,
 500                            range: text.anchor_before(range.start)..text.anchor_after(range.end),
 501                        },
 502                        text,
 503                    );
 504                }
 505                get_injections(
 506                    config,
 507                    text,
 508                    tree.root_node_with_offset(step_start_byte, step_start_point.to_ts_point()),
 509                    registry,
 510                    step.depth + 1,
 511                    &changed_ranges,
 512                    &mut combined_injection_ranges,
 513                    &mut queue,
 514                );
 515            }
 516        }
 517
 518        drop(cursor);
 519        self.layers = layers;
 520    }
 521
 522    pub fn single_tree_captures<'a>(
 523        range: Range<usize>,
 524        text: &'a Rope,
 525        tree: &'a Tree,
 526        language: &'a Arc<Language>,
 527        query: fn(&Grammar) -> Option<&Query>,
 528    ) -> SyntaxMapCaptures<'a> {
 529        SyntaxMapCaptures::new(
 530            range.clone(),
 531            text,
 532            [SyntaxLayerInfo {
 533                language,
 534                depth: 0,
 535                node: tree.root_node(),
 536            }]
 537            .into_iter(),
 538            query,
 539        )
 540    }
 541
 542    pub fn captures<'a>(
 543        &'a self,
 544        range: Range<usize>,
 545        buffer: &'a BufferSnapshot,
 546        query: fn(&Grammar) -> Option<&Query>,
 547    ) -> SyntaxMapCaptures {
 548        SyntaxMapCaptures::new(
 549            range.clone(),
 550            buffer.as_rope(),
 551            self.layers_for_range(range, buffer).into_iter(),
 552            query,
 553        )
 554    }
 555
 556    pub fn matches<'a>(
 557        &'a self,
 558        range: Range<usize>,
 559        buffer: &'a BufferSnapshot,
 560        query: fn(&Grammar) -> Option<&Query>,
 561    ) -> SyntaxMapMatches {
 562        SyntaxMapMatches::new(
 563            range.clone(),
 564            buffer.as_rope(),
 565            self.layers_for_range(range, buffer).into_iter(),
 566            query,
 567        )
 568    }
 569
 570    #[cfg(test)]
 571    pub fn layers<'a>(&'a self, buffer: &'a BufferSnapshot) -> Vec<SyntaxLayerInfo> {
 572        self.layers_for_range(0..buffer.len(), buffer).collect()
 573    }
 574
 575    pub fn layers_for_range<'a, T: ToOffset>(
 576        &'a self,
 577        range: Range<T>,
 578        buffer: &'a BufferSnapshot,
 579    ) -> impl 'a + Iterator<Item = SyntaxLayerInfo> {
 580        let start = buffer.anchor_before(range.start.to_offset(buffer));
 581        let end = buffer.anchor_after(range.end.to_offset(buffer));
 582
 583        let mut cursor = self.layers.filter::<_, ()>(move |summary| {
 584            if summary.max_depth > summary.min_depth {
 585                true
 586            } else {
 587                let is_before_start = summary.range.end.cmp(&start, buffer).is_lt();
 588                let is_after_end = summary.range.start.cmp(&end, buffer).is_gt();
 589                !is_before_start && !is_after_end
 590            }
 591        });
 592
 593        cursor.next(buffer);
 594        std::iter::from_fn(move || {
 595            if let Some(layer) = cursor.item() {
 596                let info = SyntaxLayerInfo {
 597                    language: &layer.language,
 598                    depth: layer.depth,
 599                    node: layer.tree.root_node_with_offset(
 600                        layer.range.start.to_offset(buffer),
 601                        layer.range.start.to_point(buffer).to_ts_point(),
 602                    ),
 603                };
 604                cursor.next(buffer);
 605                Some(info)
 606            } else {
 607                None
 608            }
 609        })
 610    }
 611}
 612
 613impl<'a> SyntaxMapCaptures<'a> {
 614    fn new(
 615        range: Range<usize>,
 616        text: &'a Rope,
 617        layers: impl Iterator<Item = SyntaxLayerInfo<'a>>,
 618        query: fn(&Grammar) -> Option<&Query>,
 619    ) -> Self {
 620        let mut result = Self {
 621            layers: Vec::new(),
 622            grammars: Vec::new(),
 623            active_layer_count: 0,
 624        };
 625        for SyntaxLayerInfo {
 626            language,
 627            depth,
 628            node,
 629        } in layers
 630        {
 631            let grammar = match &language.grammar {
 632                Some(grammer) => grammer,
 633                None => continue,
 634            };
 635            let query = match query(&grammar) {
 636                Some(query) => query,
 637                None => continue,
 638            };
 639
 640            let mut query_cursor = QueryCursorHandle::new();
 641
 642            // TODO - add a Tree-sitter API to remove the need for this.
 643            let cursor = unsafe {
 644                std::mem::transmute::<_, &'static mut QueryCursor>(query_cursor.deref_mut())
 645            };
 646
 647            cursor.set_byte_range(range.clone());
 648            let captures = cursor.captures(query, node, TextProvider(text));
 649            let grammar_index = result
 650                .grammars
 651                .iter()
 652                .position(|g| g.id == grammar.id())
 653                .unwrap_or_else(|| {
 654                    result.grammars.push(grammar);
 655                    result.grammars.len() - 1
 656                });
 657            let mut layer = SyntaxMapCapturesLayer {
 658                depth,
 659                grammar_index,
 660                next_capture: None,
 661                captures,
 662                _query_cursor: query_cursor,
 663            };
 664
 665            layer.advance();
 666            if layer.next_capture.is_some() {
 667                let key = layer.sort_key();
 668                let ix = match result.layers[..result.active_layer_count]
 669                    .binary_search_by_key(&key, |layer| layer.sort_key())
 670                {
 671                    Ok(ix) | Err(ix) => ix,
 672                };
 673                result.layers.insert(ix, layer);
 674                result.active_layer_count += 1;
 675            } else {
 676                result.layers.push(layer);
 677            }
 678        }
 679
 680        result
 681    }
 682
 683    pub fn grammars(&self) -> &[&'a Grammar] {
 684        &self.grammars
 685    }
 686
 687    pub fn peek(&self) -> Option<SyntaxMapCapture<'a>> {
 688        let layer = self.layers[..self.active_layer_count].first()?;
 689        let capture = layer.next_capture?;
 690        Some(SyntaxMapCapture {
 691            depth: layer.depth,
 692            grammar_index: layer.grammar_index,
 693            index: capture.index,
 694            node: capture.node,
 695        })
 696    }
 697
 698    pub fn advance(&mut self) -> bool {
 699        let layer = if let Some(layer) = self.layers[..self.active_layer_count].first_mut() {
 700            layer
 701        } else {
 702            return false;
 703        };
 704
 705        layer.advance();
 706        if layer.next_capture.is_some() {
 707            let key = layer.sort_key();
 708            let i = 1 + self.layers[1..self.active_layer_count]
 709                .iter()
 710                .position(|later_layer| key < later_layer.sort_key())
 711                .unwrap_or(self.active_layer_count - 1);
 712            self.layers[0..i].rotate_left(1);
 713        } else {
 714            self.layers[0..self.active_layer_count].rotate_left(1);
 715            self.active_layer_count -= 1;
 716        }
 717
 718        true
 719    }
 720
 721    pub fn set_byte_range(&mut self, range: Range<usize>) {
 722        for layer in &mut self.layers {
 723            layer.captures.set_byte_range(range.clone());
 724            if let Some(capture) = &layer.next_capture {
 725                if capture.node.end_byte() > range.start {
 726                    continue;
 727                }
 728            }
 729            layer.advance();
 730        }
 731        self.layers.sort_unstable_by_key(|layer| layer.sort_key());
 732        self.active_layer_count = self
 733            .layers
 734            .iter()
 735            .position(|layer| layer.next_capture.is_none())
 736            .unwrap_or(self.layers.len());
 737    }
 738}
 739
 740impl<'a> SyntaxMapMatches<'a> {
 741    fn new(
 742        range: Range<usize>,
 743        text: &'a Rope,
 744        layers: impl Iterator<Item = SyntaxLayerInfo<'a>>,
 745        query: fn(&Grammar) -> Option<&Query>,
 746    ) -> Self {
 747        let mut result = Self::default();
 748        for SyntaxLayerInfo {
 749            language,
 750            depth,
 751            node,
 752        } in layers
 753        {
 754            let grammar = match &language.grammar {
 755                Some(grammer) => grammer,
 756                None => continue,
 757            };
 758            let query = match query(&grammar) {
 759                Some(query) => query,
 760                None => continue,
 761            };
 762
 763            let mut query_cursor = QueryCursorHandle::new();
 764
 765            // TODO - add a Tree-sitter API to remove the need for this.
 766            let cursor = unsafe {
 767                std::mem::transmute::<_, &'static mut QueryCursor>(query_cursor.deref_mut())
 768            };
 769
 770            cursor.set_byte_range(range.clone());
 771            let matches = cursor.matches(query, node, TextProvider(text));
 772            let grammar_index = result
 773                .grammars
 774                .iter()
 775                .position(|g| g.id == grammar.id())
 776                .unwrap_or_else(|| {
 777                    result.grammars.push(grammar);
 778                    result.grammars.len() - 1
 779                });
 780            let mut layer = SyntaxMapMatchesLayer {
 781                depth,
 782                grammar_index,
 783                matches,
 784                next_pattern_index: 0,
 785                next_captures: Vec::new(),
 786                has_next: false,
 787                _query_cursor: query_cursor,
 788            };
 789
 790            layer.advance();
 791            if layer.has_next {
 792                let key = layer.sort_key();
 793                let ix = match result.layers[..result.active_layer_count]
 794                    .binary_search_by_key(&key, |layer| layer.sort_key())
 795                {
 796                    Ok(ix) | Err(ix) => ix,
 797                };
 798                result.layers.insert(ix, layer);
 799                result.active_layer_count += 1;
 800            } else {
 801                result.layers.push(layer);
 802            }
 803        }
 804        result
 805    }
 806
 807    pub fn grammars(&self) -> &[&'a Grammar] {
 808        &self.grammars
 809    }
 810
 811    pub fn peek(&self) -> Option<SyntaxMapMatch> {
 812        let layer = self.layers.first()?;
 813        if !layer.has_next {
 814            return None;
 815        }
 816        Some(SyntaxMapMatch {
 817            depth: layer.depth,
 818            grammar_index: layer.grammar_index,
 819            pattern_index: layer.next_pattern_index,
 820            captures: &layer.next_captures,
 821        })
 822    }
 823
 824    pub fn advance(&mut self) -> bool {
 825        let layer = if let Some(layer) = self.layers.first_mut() {
 826            layer
 827        } else {
 828            return false;
 829        };
 830
 831        layer.advance();
 832        if layer.has_next {
 833            let key = layer.sort_key();
 834            let i = 1 + self.layers[1..self.active_layer_count]
 835                .iter()
 836                .position(|later_layer| key < later_layer.sort_key())
 837                .unwrap_or(self.active_layer_count - 1);
 838            self.layers[0..i].rotate_left(1);
 839        } else {
 840            self.layers[0..self.active_layer_count].rotate_left(1);
 841            self.active_layer_count -= 1;
 842        }
 843
 844        true
 845    }
 846}
 847
 848impl<'a> SyntaxMapCapturesLayer<'a> {
 849    fn advance(&mut self) {
 850        self.next_capture = self.captures.next().map(|(mat, ix)| mat.captures[ix]);
 851    }
 852
 853    fn sort_key(&self) -> (usize, Reverse<usize>, usize) {
 854        if let Some(capture) = &self.next_capture {
 855            let range = capture.node.byte_range();
 856            (range.start, Reverse(range.end), self.depth)
 857        } else {
 858            (usize::MAX, Reverse(0), usize::MAX)
 859        }
 860    }
 861}
 862
 863impl<'a> SyntaxMapMatchesLayer<'a> {
 864    fn advance(&mut self) {
 865        if let Some(mat) = self.matches.next() {
 866            self.next_captures.clear();
 867            self.next_captures.extend_from_slice(&mat.captures);
 868            self.next_pattern_index = mat.pattern_index;
 869            self.has_next = true;
 870        } else {
 871            self.has_next = false;
 872        }
 873    }
 874
 875    fn sort_key(&self) -> (usize, Reverse<usize>, usize) {
 876        if self.has_next {
 877            let captures = &self.next_captures;
 878            if let Some((first, last)) = captures.first().zip(captures.last()) {
 879                return (
 880                    first.node.start_byte(),
 881                    Reverse(last.node.end_byte()),
 882                    self.depth,
 883                );
 884            }
 885        }
 886        (usize::MAX, Reverse(0), usize::MAX)
 887    }
 888}
 889
 890impl<'a> Iterator for SyntaxMapCaptures<'a> {
 891    type Item = SyntaxMapCapture<'a>;
 892
 893    fn next(&mut self) -> Option<Self::Item> {
 894        let result = self.peek();
 895        self.advance();
 896        result
 897    }
 898}
 899
 900fn join_ranges(
 901    a: impl Iterator<Item = Range<usize>>,
 902    b: impl Iterator<Item = Range<usize>>,
 903) -> Vec<Range<usize>> {
 904    let mut result = Vec::<Range<usize>>::new();
 905    let mut a = a.peekable();
 906    let mut b = b.peekable();
 907    loop {
 908        let range = match (a.peek(), b.peek()) {
 909            (Some(range_a), Some(range_b)) => {
 910                if range_a.start < range_b.start {
 911                    a.next().unwrap()
 912                } else {
 913                    b.next().unwrap()
 914                }
 915            }
 916            (None, Some(_)) => b.next().unwrap(),
 917            (Some(_), None) => a.next().unwrap(),
 918            (None, None) => break,
 919        };
 920
 921        if let Some(last) = result.last_mut() {
 922            if range.start <= last.end {
 923                last.end = last.end.max(range.end);
 924                continue;
 925            }
 926        }
 927        result.push(range);
 928    }
 929    result
 930}
 931
 932fn parse_text(
 933    grammar: &Grammar,
 934    text: &Rope,
 935    start_byte: usize,
 936    start_point: Point,
 937    mut ranges: Vec<tree_sitter::Range>,
 938    old_tree: Option<Tree>,
 939) -> Tree {
 940    for range in &mut ranges {
 941        range.start_byte -= start_byte;
 942        range.end_byte -= start_byte;
 943        range.start_point = (Point::from_ts_point(range.start_point) - start_point).to_ts_point();
 944        range.end_point = (Point::from_ts_point(range.end_point) - start_point).to_ts_point();
 945    }
 946
 947    PARSER.with(|parser| {
 948        let mut parser = parser.borrow_mut();
 949        let mut chunks = text.chunks_in_range(start_byte..text.len());
 950        parser
 951            .set_included_ranges(&ranges)
 952            .expect("overlapping ranges");
 953        parser
 954            .set_language(grammar.ts_language)
 955            .expect("incompatible grammar");
 956        parser
 957            .parse_with(
 958                &mut move |offset, _| {
 959                    chunks.seek(start_byte + offset);
 960                    chunks.next().unwrap_or("").as_bytes()
 961                },
 962                old_tree.as_ref(),
 963            )
 964            .expect("invalid language")
 965    })
 966}
 967
 968fn get_injections(
 969    config: &InjectionConfig,
 970    text: &BufferSnapshot,
 971    node: Node,
 972    language_registry: &LanguageRegistry,
 973    depth: usize,
 974    changed_ranges: &[Range<usize>],
 975    combined_injection_ranges: &mut HashMap<Arc<Language>, Vec<tree_sitter::Range>>,
 976    queue: &mut BinaryHeap<ParseStep>,
 977) -> bool {
 978    let mut result = false;
 979    let mut query_cursor = QueryCursorHandle::new();
 980    let mut prev_match = None;
 981
 982    combined_injection_ranges.clear();
 983    for pattern in &config.patterns {
 984        if let (Some(language_name), true) = (pattern.language.as_ref(), pattern.combined) {
 985            if let Some(language) = language_registry.get_language(language_name) {
 986                combined_injection_ranges.insert(language, Vec::new());
 987            }
 988        }
 989    }
 990
 991    for query_range in changed_ranges {
 992        query_cursor.set_byte_range(query_range.start.saturating_sub(1)..query_range.end);
 993        for mat in query_cursor.matches(&config.query, node, TextProvider(text.as_rope())) {
 994            let content_ranges = mat
 995                .nodes_for_capture_index(config.content_capture_ix)
 996                .map(|node| node.range())
 997                .collect::<Vec<_>>();
 998            if content_ranges.is_empty() {
 999                continue;
1000            }
1001
1002            // Avoid duplicate matches if two changed ranges intersect the same injection.
1003            let content_range =
1004                content_ranges.first().unwrap().start_byte..content_ranges.last().unwrap().end_byte;
1005            if let Some((last_pattern_ix, last_range)) = &prev_match {
1006                if mat.pattern_index == *last_pattern_ix && content_range == *last_range {
1007                    continue;
1008                }
1009            }
1010            prev_match = Some((mat.pattern_index, content_range.clone()));
1011
1012            let combined = config.patterns[mat.pattern_index].combined;
1013            let language_name = config.patterns[mat.pattern_index]
1014                .language
1015                .as_ref()
1016                .map(|s| Cow::Borrowed(s.as_ref()))
1017                .or_else(|| {
1018                    let ix = config.language_capture_ix?;
1019                    let node = mat.nodes_for_capture_index(ix).next()?;
1020                    Some(Cow::Owned(text.text_for_range(node.byte_range()).collect()))
1021                });
1022
1023            if let Some(language_name) = language_name {
1024                if let Some(language) = language_registry.get_language(language_name.as_ref()) {
1025                    result = true;
1026                    let range = text.anchor_before(content_range.start)
1027                        ..text.anchor_after(content_range.end);
1028                    if combined {
1029                        combined_injection_ranges
1030                            .get_mut(&language.clone())
1031                            .unwrap()
1032                            .extend(content_ranges);
1033                    } else {
1034                        queue.push(ParseStep {
1035                            depth,
1036                            language,
1037                            included_ranges: content_ranges,
1038                            range,
1039                            mode: ParseMode::Single,
1040                        });
1041                    }
1042                }
1043            }
1044        }
1045    }
1046
1047    for (language, mut included_ranges) in combined_injection_ranges.drain() {
1048        included_ranges.sort_unstable();
1049        let range = text.anchor_before(node.start_byte())..text.anchor_after(node.end_byte());
1050        queue.push(ParseStep {
1051            depth,
1052            language,
1053            range,
1054            included_ranges,
1055            mode: ParseMode::Combined {
1056                parent_layer_range: node.start_byte()..node.end_byte(),
1057                parent_layer_changed_ranges: changed_ranges.to_vec(),
1058            },
1059        })
1060    }
1061
1062    result
1063}
1064
1065fn splice_included_ranges(
1066    mut ranges: Vec<tree_sitter::Range>,
1067    changed_ranges: &[Range<usize>],
1068    new_ranges: &[tree_sitter::Range],
1069) -> Vec<tree_sitter::Range> {
1070    let mut changed_ranges = changed_ranges.into_iter().peekable();
1071    let mut new_ranges = new_ranges.into_iter().peekable();
1072    let mut ranges_ix = 0;
1073    loop {
1074        let new_range = new_ranges.peek();
1075        let mut changed_range = changed_ranges.peek();
1076
1077        // process changed ranges before any overlapping new ranges
1078        if let Some((changed, new)) = changed_range.zip(new_range) {
1079            if new.end_byte < changed.start {
1080                changed_range = None;
1081            }
1082        }
1083
1084        if let Some(changed) = changed_range {
1085            let mut start_ix = ranges_ix
1086                + match ranges[ranges_ix..].binary_search_by_key(&changed.start, |r| r.end_byte) {
1087                    Ok(ix) | Err(ix) => ix,
1088                };
1089            let mut end_ix = ranges_ix
1090                + match ranges[ranges_ix..].binary_search_by_key(&changed.end, |r| r.start_byte) {
1091                    Ok(ix) => ix + 1,
1092                    Err(ix) => ix,
1093                };
1094
1095            // If there are empty ranges, then there may be multiple ranges with the same
1096            // start or end. Expand the splice to include any adjacent ranges. That touch
1097            // the changed range.
1098            while start_ix > 0 {
1099                if ranges[start_ix - 1].end_byte == changed.start {
1100                    start_ix -= 1;
1101                } else {
1102                    break;
1103                }
1104            }
1105            while let Some(range) = ranges.get(end_ix) {
1106                if range.start_byte == changed.end {
1107                    end_ix += 1;
1108                } else {
1109                    break;
1110                }
1111            }
1112
1113            if end_ix > start_ix {
1114                ranges.splice(start_ix..end_ix, []);
1115            }
1116            changed_ranges.next();
1117            ranges_ix = start_ix;
1118        } else if let Some(new_range) = new_range {
1119            let ix = ranges_ix
1120                + match ranges[ranges_ix..]
1121                    .binary_search_by_key(&new_range.start_byte, |r| r.start_byte)
1122                {
1123                    Ok(ix) | Err(ix) => ix,
1124                };
1125            ranges.insert(ix, **new_range);
1126            new_ranges.next();
1127            ranges_ix = ix + 1;
1128        } else {
1129            break;
1130        }
1131    }
1132    ranges
1133}
1134
1135impl std::ops::Deref for SyntaxMap {
1136    type Target = SyntaxSnapshot;
1137
1138    fn deref(&self) -> &Self::Target {
1139        &self.snapshot
1140    }
1141}
1142
1143impl PartialEq for ParseStep {
1144    fn eq(&self, _: &Self) -> bool {
1145        false
1146    }
1147}
1148
1149impl Eq for ParseStep {}
1150
1151impl PartialOrd for ParseStep {
1152    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1153        Some(self.cmp(&other))
1154    }
1155}
1156
1157impl Ord for ParseStep {
1158    fn cmp(&self, other: &Self) -> Ordering {
1159        let range_a = self.range();
1160        let range_b = other.range();
1161        Ord::cmp(&other.depth, &self.depth)
1162            .then_with(|| Ord::cmp(&range_b.start, &range_a.start))
1163            .then_with(|| Ord::cmp(&range_a.end, &range_b.end))
1164            .then_with(|| self.language.id().cmp(&other.language.id()))
1165    }
1166}
1167
1168impl ParseStep {
1169    fn range(&self) -> Range<usize> {
1170        if let ParseMode::Combined {
1171            parent_layer_range, ..
1172        } = &self.mode
1173        {
1174            parent_layer_range.clone()
1175        } else {
1176            let start = self.included_ranges.first().map_or(0, |r| r.start_byte);
1177            let end = self.included_ranges.last().map_or(0, |r| r.end_byte);
1178            start..end
1179        }
1180    }
1181}
1182
1183impl ChangedRegion {
1184    fn cmp(&self, other: &Self, buffer: &BufferSnapshot) -> Ordering {
1185        let range_a = &self.range;
1186        let range_b = &other.range;
1187        Ord::cmp(&self.depth, &other.depth)
1188            .then_with(|| range_a.start.cmp(&range_b.start, buffer))
1189            .then_with(|| range_b.end.cmp(&range_a.end, buffer))
1190    }
1191}
1192
1193impl ChangeRegionSet {
1194    fn start_position(&self) -> DepthAndMaxPosition {
1195        self.0
1196            .first()
1197            .map_or(DepthAndMaxPosition(usize::MAX, Anchor::MAX), |region| {
1198                DepthAndMaxPosition(region.depth, region.range.start)
1199            })
1200    }
1201
1202    fn intersects(&self, layer: &SyntaxLayer, text: &BufferSnapshot) -> bool {
1203        for region in &self.0 {
1204            if region.depth < layer.depth {
1205                continue;
1206            }
1207            if region.depth > layer.depth {
1208                break;
1209            }
1210            if region.range.end.cmp(&layer.range.start, text).is_le() {
1211                continue;
1212            }
1213            if region.range.start.cmp(&layer.range.end, text).is_ge() {
1214                break;
1215            }
1216            return true;
1217        }
1218        false
1219    }
1220
1221    fn insert(&mut self, region: ChangedRegion, text: &BufferSnapshot) {
1222        if let Err(ix) = self.0.binary_search_by(|probe| probe.cmp(&region, text)) {
1223            self.0.insert(ix, region);
1224        }
1225    }
1226
1227    fn prune(&mut self, summary: SyntaxLayerSummary, text: &BufferSnapshot) -> bool {
1228        let prev_len = self.0.len();
1229        self.0.retain(|region| {
1230            region.depth > summary.max_depth
1231                || (region.depth == summary.max_depth
1232                    && region
1233                        .range
1234                        .end
1235                        .cmp(&summary.last_layer_range.start, text)
1236                        .is_gt())
1237        });
1238        self.0.len() < prev_len
1239    }
1240}
1241
1242impl Default for SyntaxLayerSummary {
1243    fn default() -> Self {
1244        Self {
1245            max_depth: 0,
1246            min_depth: 0,
1247            range: Anchor::MAX..Anchor::MIN,
1248            last_layer_range: Anchor::MIN..Anchor::MAX,
1249            last_layer_language: None,
1250        }
1251    }
1252}
1253
1254impl sum_tree::Summary for SyntaxLayerSummary {
1255    type Context = BufferSnapshot;
1256
1257    fn add_summary(&mut self, other: &Self, buffer: &Self::Context) {
1258        if other.max_depth > self.max_depth {
1259            self.max_depth = other.max_depth;
1260            self.range = other.range.clone();
1261        } else {
1262            if other.range.start.cmp(&self.range.start, buffer).is_lt() {
1263                self.range.start = other.range.start;
1264            }
1265            if other.range.end.cmp(&self.range.end, buffer).is_gt() {
1266                self.range.end = other.range.end;
1267            }
1268        }
1269        self.last_layer_range = other.last_layer_range.clone();
1270        self.last_layer_language = other.last_layer_language;
1271    }
1272}
1273
1274impl<'a> SeekTarget<'a, SyntaxLayerSummary, SyntaxLayerSummary> for SyntaxLayerPosition {
1275    fn cmp(&self, cursor_location: &SyntaxLayerSummary, buffer: &BufferSnapshot) -> Ordering {
1276        Ord::cmp(&self.depth, &cursor_location.max_depth)
1277            .then_with(|| {
1278                self.range
1279                    .start
1280                    .cmp(&cursor_location.last_layer_range.start, buffer)
1281            })
1282            .then_with(|| {
1283                cursor_location
1284                    .last_layer_range
1285                    .end
1286                    .cmp(&self.range.end, buffer)
1287            })
1288            .then_with(|| self.language.cmp(&cursor_location.last_layer_language))
1289    }
1290}
1291
1292impl<'a> SeekTarget<'a, SyntaxLayerSummary, SyntaxLayerSummary> for DepthAndMaxPosition {
1293    fn cmp(&self, cursor_location: &SyntaxLayerSummary, text: &BufferSnapshot) -> Ordering {
1294        Ord::cmp(&self.0, &cursor_location.max_depth)
1295            .then_with(|| self.1.cmp(&cursor_location.range.end, text))
1296    }
1297}
1298
1299impl<'a> SeekTarget<'a, SyntaxLayerSummary, SyntaxLayerSummary>
1300    for SyntaxLayerPositionBeforeChange
1301{
1302    fn cmp(&self, cursor_location: &SyntaxLayerSummary, buffer: &BufferSnapshot) -> Ordering {
1303        if self.change.cmp(cursor_location, buffer).is_le() {
1304            return Ordering::Less;
1305        } else {
1306            self.position.cmp(cursor_location, buffer)
1307        }
1308    }
1309}
1310
1311impl sum_tree::Item for SyntaxLayer {
1312    type Summary = SyntaxLayerSummary;
1313
1314    fn summary(&self) -> Self::Summary {
1315        SyntaxLayerSummary {
1316            min_depth: self.depth,
1317            max_depth: self.depth,
1318            range: self.range.clone(),
1319            last_layer_range: self.range.clone(),
1320            last_layer_language: self.language.id(),
1321        }
1322    }
1323}
1324
1325impl std::fmt::Debug for SyntaxLayer {
1326    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1327        f.debug_struct("SyntaxLayer")
1328            .field("depth", &self.depth)
1329            .field("range", &self.range)
1330            .field("tree", &self.tree)
1331            .finish()
1332    }
1333}
1334
1335impl<'a> tree_sitter::TextProvider<'a> for TextProvider<'a> {
1336    type I = ByteChunks<'a>;
1337
1338    fn text(&mut self, node: tree_sitter::Node) -> Self::I {
1339        ByteChunks(self.0.chunks_in_range(node.byte_range()))
1340    }
1341}
1342
1343impl<'a> Iterator for ByteChunks<'a> {
1344    type Item = &'a [u8];
1345
1346    fn next(&mut self) -> Option<Self::Item> {
1347        self.0.next().map(str::as_bytes)
1348    }
1349}
1350
1351impl QueryCursorHandle {
1352    pub(crate) fn new() -> Self {
1353        let mut cursor = QUERY_CURSORS.lock().pop().unwrap_or_else(QueryCursor::new);
1354        cursor.set_match_limit(64);
1355        QueryCursorHandle(Some(cursor))
1356    }
1357}
1358
1359impl Deref for QueryCursorHandle {
1360    type Target = QueryCursor;
1361
1362    fn deref(&self) -> &Self::Target {
1363        self.0.as_ref().unwrap()
1364    }
1365}
1366
1367impl DerefMut for QueryCursorHandle {
1368    fn deref_mut(&mut self) -> &mut Self::Target {
1369        self.0.as_mut().unwrap()
1370    }
1371}
1372
1373impl Drop for QueryCursorHandle {
1374    fn drop(&mut self) {
1375        let mut cursor = self.0.take().unwrap();
1376        cursor.set_byte_range(0..usize::MAX);
1377        cursor.set_point_range(Point::zero().to_ts_point()..Point::MAX.to_ts_point());
1378        QUERY_CURSORS.lock().push(cursor)
1379    }
1380}
1381
1382pub(crate) trait ToTreeSitterPoint {
1383    fn to_ts_point(self) -> tree_sitter::Point;
1384    fn from_ts_point(point: tree_sitter::Point) -> Self;
1385}
1386
1387impl ToTreeSitterPoint for Point {
1388    fn to_ts_point(self) -> tree_sitter::Point {
1389        tree_sitter::Point::new(self.row as usize, self.column as usize)
1390    }
1391
1392    fn from_ts_point(point: tree_sitter::Point) -> Self {
1393        Point::new(point.row as u32, point.column as u32)
1394    }
1395}
1396
1397#[cfg(test)]
1398mod tests {
1399    use super::*;
1400    use crate::LanguageConfig;
1401    use rand::rngs::StdRng;
1402    use std::env;
1403    use text::Buffer;
1404    use unindent::Unindent as _;
1405    use util::test::marked_text_ranges;
1406
1407    #[test]
1408    fn test_splice_included_ranges() {
1409        let ranges = vec![ts_range(20..30), ts_range(50..60), ts_range(80..90)];
1410
1411        let new_ranges = splice_included_ranges(
1412            ranges.clone(),
1413            &[54..56, 58..68],
1414            &[ts_range(50..54), ts_range(59..67)],
1415        );
1416        assert_eq!(
1417            new_ranges,
1418            &[
1419                ts_range(20..30),
1420                ts_range(50..54),
1421                ts_range(59..67),
1422                ts_range(80..90),
1423            ]
1424        );
1425
1426        let new_ranges = splice_included_ranges(ranges.clone(), &[70..71, 91..100], &[]);
1427        assert_eq!(
1428            new_ranges,
1429            &[ts_range(20..30), ts_range(50..60), ts_range(80..90)]
1430        );
1431
1432        let new_ranges =
1433            splice_included_ranges(ranges.clone(), &[], &[ts_range(0..2), ts_range(70..75)]);
1434        assert_eq!(
1435            new_ranges,
1436            &[
1437                ts_range(0..2),
1438                ts_range(20..30),
1439                ts_range(50..60),
1440                ts_range(70..75),
1441                ts_range(80..90)
1442            ]
1443        );
1444
1445        let new_ranges = splice_included_ranges(ranges.clone(), &[30..50], &[ts_range(25..55)]);
1446        assert_eq!(new_ranges, &[ts_range(25..55), ts_range(80..90)]);
1447
1448        fn ts_range(range: Range<usize>) -> tree_sitter::Range {
1449            tree_sitter::Range {
1450                start_byte: range.start,
1451                start_point: tree_sitter::Point {
1452                    row: 0,
1453                    column: range.start,
1454                },
1455                end_byte: range.end,
1456                end_point: tree_sitter::Point {
1457                    row: 0,
1458                    column: range.end,
1459                },
1460            }
1461        }
1462    }
1463
1464    #[gpui::test]
1465    fn test_syntax_map_layers_for_range() {
1466        let registry = Arc::new(LanguageRegistry::test());
1467        let language = Arc::new(rust_lang());
1468        registry.add(language.clone());
1469
1470        let mut buffer = Buffer::new(
1471            0,
1472            0,
1473            r#"
1474                fn a() {
1475                    assert_eq!(
1476                        b(vec![C {}]),
1477                        vec![d.e],
1478                    );
1479                    println!("{}", f(|_| true));
1480                }
1481            "#
1482            .unindent(),
1483        );
1484
1485        let mut syntax_map = SyntaxMap::new();
1486        syntax_map.set_language_registry(registry.clone());
1487        syntax_map.reparse(language.clone(), &buffer);
1488
1489        assert_layers_for_range(
1490            &syntax_map,
1491            &buffer,
1492            Point::new(2, 0)..Point::new(2, 0),
1493            &[
1494                "...(function_item ... (block (expression_statement (macro_invocation...",
1495                "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
1496            ],
1497        );
1498        assert_layers_for_range(
1499            &syntax_map,
1500            &buffer,
1501            Point::new(2, 14)..Point::new(2, 16),
1502            &[
1503                "...(function_item ...",
1504                "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
1505                "...(array_expression (struct_expression ...",
1506            ],
1507        );
1508        assert_layers_for_range(
1509            &syntax_map,
1510            &buffer,
1511            Point::new(3, 14)..Point::new(3, 16),
1512            &[
1513                "...(function_item ...",
1514                "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
1515                "...(array_expression (field_expression ...",
1516            ],
1517        );
1518        assert_layers_for_range(
1519            &syntax_map,
1520            &buffer,
1521            Point::new(5, 12)..Point::new(5, 16),
1522            &[
1523                "...(function_item ...",
1524                "...(call_expression ... (arguments (closure_expression ...",
1525            ],
1526        );
1527
1528        // Replace a vec! macro invocation with a plain slice, removing a syntactic layer.
1529        let macro_name_range = range_for_text(&buffer, "vec!");
1530        buffer.edit([(macro_name_range, "&")]);
1531        syntax_map.interpolate(&buffer);
1532        syntax_map.reparse(language.clone(), &buffer);
1533
1534        assert_layers_for_range(
1535            &syntax_map,
1536            &buffer,
1537            Point::new(2, 14)..Point::new(2, 16),
1538            &[
1539                "...(function_item ...",
1540                "...(tuple_expression (call_expression ... arguments: (arguments (reference_expression value: (array_expression...",
1541            ],
1542        );
1543
1544        // Put the vec! macro back, adding back the syntactic layer.
1545        buffer.undo();
1546        syntax_map.interpolate(&buffer);
1547        syntax_map.reparse(language.clone(), &buffer);
1548
1549        assert_layers_for_range(
1550            &syntax_map,
1551            &buffer,
1552            Point::new(2, 14)..Point::new(2, 16),
1553            &[
1554                "...(function_item ...",
1555                "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
1556                "...(array_expression (struct_expression ...",
1557            ],
1558        );
1559    }
1560
1561    #[gpui::test]
1562    fn test_typing_multiple_new_injections() {
1563        let (buffer, syntax_map) = test_edit_sequence(
1564            "Rust",
1565            &[
1566                "fn a() { dbg }",
1567                "fn a() { dbg«!» }",
1568                "fn a() { dbg!«()» }",
1569                "fn a() { dbg!(«b») }",
1570                "fn a() { dbg!(b«.») }",
1571                "fn a() { dbg!(b.«c») }",
1572                "fn a() { dbg!(b.c«()») }",
1573                "fn a() { dbg!(b.c(«vec»)) }",
1574                "fn a() { dbg!(b.c(vec«!»)) }",
1575                "fn a() { dbg!(b.c(vec!«[]»)) }",
1576                "fn a() { dbg!(b.c(vec![«d»])) }",
1577                "fn a() { dbg!(b.c(vec![d«.»])) }",
1578                "fn a() { dbg!(b.c(vec![d.«e»])) }",
1579            ],
1580        );
1581
1582        assert_capture_ranges(
1583            &syntax_map,
1584            &buffer,
1585            &["field"],
1586            "fn a() { dbg!(b.«c»(vec![d.«e»])) }",
1587        );
1588    }
1589
1590    #[gpui::test]
1591    fn test_pasting_new_injection_line_between_others() {
1592        let (buffer, syntax_map) = test_edit_sequence(
1593            "Rust",
1594            &[
1595                "
1596                    fn a() {
1597                        b!(B {});
1598                        c!(C {});
1599                        d!(D {});
1600                        e!(E {});
1601                        f!(F {});
1602                        g!(G {});
1603                    }
1604                ",
1605                "
1606                    fn a() {
1607                        b!(B {});
1608                        c!(C {});
1609                        d!(D {});
1610                    «    h!(H {});
1611                    »    e!(E {});
1612                        f!(F {});
1613                        g!(G {});
1614                    }
1615                ",
1616            ],
1617        );
1618
1619        assert_capture_ranges(
1620            &syntax_map,
1621            &buffer,
1622            &["struct"],
1623            "
1624            fn a() {
1625                b!(«B {}»);
1626                c!(«C {}»);
1627                d!(«D {}»);
1628                h!(«H {}»);
1629                e!(«E {}»);
1630                f!(«F {}»);
1631                g!(«G {}»);
1632            }
1633            ",
1634        );
1635    }
1636
1637    #[gpui::test]
1638    fn test_joining_injections_with_child_injections() {
1639        let (buffer, syntax_map) = test_edit_sequence(
1640            "Rust",
1641            &[
1642                "
1643                    fn a() {
1644                        b!(
1645                            c![one.two.three],
1646                            d![four.five.six],
1647                        );
1648                        e!(
1649                            f![seven.eight],
1650                        );
1651                    }
1652                ",
1653                "
1654                    fn a() {
1655                        b!(
1656                            c![one.two.three],
1657                            d![four.five.six],
1658                        ˇ    f![seven.eight],
1659                        );
1660                    }
1661                ",
1662            ],
1663        );
1664
1665        assert_capture_ranges(
1666            &syntax_map,
1667            &buffer,
1668            &["field"],
1669            "
1670            fn a() {
1671                b!(
1672                    c![one.«two».«three»],
1673                    d![four.«five».«six»],
1674                    f![seven.«eight»],
1675                );
1676            }
1677            ",
1678        );
1679    }
1680
1681    #[gpui::test]
1682    fn test_editing_edges_of_injection() {
1683        test_edit_sequence(
1684            "Rust",
1685            &[
1686                "
1687                    fn a() {
1688                        b!(c!())
1689                    }
1690                ",
1691                "
1692                    fn a() {
1693                        «d»!(c!())
1694                    }
1695                ",
1696                "
1697                    fn a() {
1698                        «e»d!(c!())
1699                    }
1700                ",
1701                "
1702                    fn a() {
1703                        ed!«[»c!()«]»
1704                    }
1705            ",
1706            ],
1707        );
1708    }
1709
1710    #[gpui::test]
1711    fn test_edits_preceding_and_intersecting_injection() {
1712        test_edit_sequence(
1713            "Rust",
1714            &[
1715                //
1716                "const aaaaaaaaaaaa: B = c!(d(e.f));",
1717                "const aˇa: B = c!(d(eˇ));",
1718            ],
1719        );
1720    }
1721
1722    #[gpui::test]
1723    fn test_non_local_changes_create_injections() {
1724        test_edit_sequence(
1725            "Rust",
1726            &[
1727                "
1728                    // a! {
1729                        static B: C = d;
1730                    // }
1731                ",
1732                "
1733                    ˇa! {
1734                        static B: C = d;
1735                    ˇ}
1736                ",
1737            ],
1738        );
1739    }
1740
1741    #[gpui::test]
1742    fn test_creating_many_injections_in_one_edit() {
1743        test_edit_sequence(
1744            "Rust",
1745            &[
1746                "
1747                    fn a() {
1748                        one(Two::three(3));
1749                        four(Five::six(6));
1750                        seven(Eight::nine(9));
1751                    }
1752                ",
1753                "
1754                    fn a() {
1755                        one«!»(Two::three(3));
1756                        four«!»(Five::six(6));
1757                        seven«!»(Eight::nine(9));
1758                    }
1759                ",
1760                "
1761                    fn a() {
1762                        one!(Two::three«!»(3));
1763                        four!(Five::six«!»(6));
1764                        seven!(Eight::nine«!»(9));
1765                    }
1766                ",
1767            ],
1768        );
1769    }
1770
1771    #[gpui::test]
1772    fn test_editing_across_injection_boundary() {
1773        test_edit_sequence(
1774            "Rust",
1775            &[
1776                "
1777                    fn one() {
1778                        two();
1779                        three!(
1780                            three.four,
1781                            five.six,
1782                        );
1783                    }
1784                ",
1785                "
1786                    fn one() {
1787                        two();
1788                        th«irty_five![»
1789                            three.four,
1790                            five.six,
1791                        «   seven.eight,
1792                        ];»
1793                    }
1794                ",
1795            ],
1796        );
1797    }
1798
1799    #[gpui::test]
1800    fn test_removing_injection_by_replacing_across_boundary() {
1801        test_edit_sequence(
1802            "Rust",
1803            &[
1804                "
1805                    fn one() {
1806                        two!(
1807                            three.four,
1808                        );
1809                    }
1810                ",
1811                "
1812                    fn one() {
1813                        t«en
1814                            .eleven(
1815                            twelve,
1816                        »
1817                            three.four,
1818                        );
1819                    }
1820                ",
1821            ],
1822        );
1823    }
1824
1825    #[gpui::test]
1826    fn test_combined_injections() {
1827        let (buffer, syntax_map) = test_edit_sequence(
1828            "ERB",
1829            &[
1830                "
1831                    <body>
1832                        <% if @one %>
1833                            <div class=one>
1834                        <% else %>
1835                            <div class=two>
1836                        <% end %>
1837                        </div>
1838                    </body>
1839                ",
1840                "
1841                    <body>
1842                        <% if @one %>
1843                            <div class=one>
1844                        ˇ else ˇ
1845                            <div class=two>
1846                        <% end %>
1847                        </div>
1848                    </body>
1849                ",
1850                "
1851                    <body>
1852                        <% if @one «;» end %>
1853                        </div>
1854                    </body>
1855                ",
1856            ],
1857        );
1858
1859        assert_capture_ranges(
1860            &syntax_map,
1861            &buffer,
1862            &["tag", "ivar"],
1863            "
1864                <«body»>
1865                    <% if «@one» ; end %>
1866                    </«div»>
1867                </«body»>
1868            ",
1869        );
1870    }
1871
1872    #[gpui::test]
1873    fn test_combined_injections_empty_ranges() {
1874        test_edit_sequence(
1875            "ERB",
1876            &[
1877                "
1878                    <% if @one %>
1879                    <% else %>
1880                    <% end %>
1881                ",
1882                "
1883                    <% if @one %>
1884                    ˇ<% end %>
1885                ",
1886            ],
1887        );
1888    }
1889
1890    #[gpui::test(iterations = 100)]
1891    fn test_random_syntax_map_edits(mut rng: StdRng) {
1892        let operations = env::var("OPERATIONS")
1893            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1894            .unwrap_or(10);
1895
1896        let text = r#"
1897            fn test_something() {
1898                let vec = vec![5, 1, 3, 8];
1899                assert_eq!(
1900                    vec
1901                        .into_iter()
1902                        .map(|i| i * 2)
1903                        .collect::<Vec<usize>>(),
1904                    vec![
1905                        5 * 2, 1 * 2, 3 * 2, 8 * 2
1906                    ],
1907                );
1908            }
1909        "#
1910        .unindent()
1911        .repeat(2);
1912
1913        let registry = Arc::new(LanguageRegistry::test());
1914        let language = Arc::new(rust_lang());
1915        registry.add(language.clone());
1916        let mut buffer = Buffer::new(0, 0, text);
1917
1918        let mut syntax_map = SyntaxMap::new();
1919        syntax_map.set_language_registry(registry.clone());
1920        syntax_map.reparse(language.clone(), &buffer);
1921
1922        let mut reference_syntax_map = SyntaxMap::new();
1923        reference_syntax_map.set_language_registry(registry.clone());
1924
1925        log::info!("initial text:\n{}", buffer.text());
1926
1927        for _ in 0..operations {
1928            let prev_buffer = buffer.snapshot();
1929            let prev_syntax_map = syntax_map.snapshot();
1930
1931            buffer.randomly_edit(&mut rng, 3);
1932            log::info!("text:\n{}", buffer.text());
1933
1934            syntax_map.interpolate(&buffer);
1935            check_interpolation(&prev_syntax_map, &syntax_map, &prev_buffer, &buffer);
1936
1937            syntax_map.reparse(language.clone(), &buffer);
1938
1939            reference_syntax_map.clear();
1940            reference_syntax_map.reparse(language.clone(), &buffer);
1941        }
1942
1943        for i in 0..operations {
1944            let i = operations - i - 1;
1945            buffer.undo();
1946            log::info!("undoing operation {}", i);
1947            log::info!("text:\n{}", buffer.text());
1948
1949            syntax_map.interpolate(&buffer);
1950            syntax_map.reparse(language.clone(), &buffer);
1951
1952            reference_syntax_map.clear();
1953            reference_syntax_map.reparse(language.clone(), &buffer);
1954            assert_eq!(
1955                syntax_map.layers(&buffer).len(),
1956                reference_syntax_map.layers(&buffer).len(),
1957                "wrong number of layers after undoing edit {i}"
1958            );
1959        }
1960
1961        let layers = syntax_map.layers(&buffer);
1962        let reference_layers = reference_syntax_map.layers(&buffer);
1963        for (edited_layer, reference_layer) in layers.into_iter().zip(reference_layers.into_iter())
1964        {
1965            assert_eq!(edited_layer.node.to_sexp(), reference_layer.node.to_sexp());
1966            assert_eq!(edited_layer.node.range(), reference_layer.node.range());
1967        }
1968    }
1969
1970    fn check_interpolation(
1971        old_syntax_map: &SyntaxSnapshot,
1972        new_syntax_map: &SyntaxSnapshot,
1973        old_buffer: &BufferSnapshot,
1974        new_buffer: &BufferSnapshot,
1975    ) {
1976        let edits = new_buffer
1977            .edits_since::<usize>(&old_buffer.version())
1978            .collect::<Vec<_>>();
1979
1980        for (old_layer, new_layer) in old_syntax_map
1981            .layers
1982            .iter()
1983            .zip(new_syntax_map.layers.iter())
1984        {
1985            assert_eq!(old_layer.range, new_layer.range);
1986            let old_start_byte = old_layer.range.start.to_offset(old_buffer);
1987            let new_start_byte = new_layer.range.start.to_offset(new_buffer);
1988            let old_start_point = old_layer.range.start.to_point(old_buffer).to_ts_point();
1989            let new_start_point = new_layer.range.start.to_point(new_buffer).to_ts_point();
1990            let old_node = old_layer
1991                .tree
1992                .root_node_with_offset(old_start_byte, old_start_point);
1993            let new_node = new_layer
1994                .tree
1995                .root_node_with_offset(new_start_byte, new_start_point);
1996            check_node_edits(
1997                old_layer.depth,
1998                &old_layer.range,
1999                old_node,
2000                new_node,
2001                old_buffer,
2002                new_buffer,
2003                &edits,
2004            );
2005        }
2006
2007        fn check_node_edits(
2008            depth: usize,
2009            range: &Range<Anchor>,
2010            old_node: Node,
2011            new_node: Node,
2012            old_buffer: &BufferSnapshot,
2013            new_buffer: &BufferSnapshot,
2014            edits: &[text::Edit<usize>],
2015        ) {
2016            assert_eq!(old_node.kind(), new_node.kind());
2017
2018            let old_range = old_node.byte_range();
2019            let new_range = new_node.byte_range();
2020
2021            let is_edited = edits
2022                .iter()
2023                .any(|edit| edit.new.start < new_range.end && edit.new.end > new_range.start);
2024            if is_edited {
2025                assert!(
2026                    new_node.has_changes(),
2027                    concat!(
2028                        "failed to mark node as edited.\n",
2029                        "layer depth: {}, old layer range: {:?}, new layer range: {:?},\n",
2030                        "node kind: {}, old node range: {:?}, new node range: {:?}",
2031                    ),
2032                    depth,
2033                    range.to_offset(old_buffer),
2034                    range.to_offset(new_buffer),
2035                    new_node.kind(),
2036                    old_range,
2037                    new_range,
2038                );
2039            }
2040
2041            if !new_node.has_changes() {
2042                assert_eq!(
2043                    old_buffer
2044                        .text_for_range(old_range.clone())
2045                        .collect::<String>(),
2046                    new_buffer
2047                        .text_for_range(new_range.clone())
2048                        .collect::<String>(),
2049                    concat!(
2050                        "mismatched text for node\n",
2051                        "layer depth: {}, old layer range: {:?}, new layer range: {:?},\n",
2052                        "node kind: {}, old node range:{:?}, new node range:{:?}",
2053                    ),
2054                    depth,
2055                    range.to_offset(old_buffer),
2056                    range.to_offset(new_buffer),
2057                    new_node.kind(),
2058                    old_range,
2059                    new_range,
2060                );
2061            }
2062
2063            for i in 0..new_node.child_count() {
2064                check_node_edits(
2065                    depth,
2066                    range,
2067                    old_node.child(i).unwrap(),
2068                    new_node.child(i).unwrap(),
2069                    old_buffer,
2070                    new_buffer,
2071                    edits,
2072                )
2073            }
2074        }
2075    }
2076
2077    fn test_edit_sequence(language_name: &str, steps: &[&str]) -> (Buffer, SyntaxMap) {
2078        let registry = Arc::new(LanguageRegistry::test());
2079        registry.add(Arc::new(rust_lang()));
2080        registry.add(Arc::new(ruby_lang()));
2081        registry.add(Arc::new(html_lang()));
2082        registry.add(Arc::new(erb_lang()));
2083        let language = registry.get_language(language_name).unwrap();
2084        let mut buffer = Buffer::new(0, 0, Default::default());
2085
2086        let mut mutated_syntax_map = SyntaxMap::new();
2087        mutated_syntax_map.set_language_registry(registry.clone());
2088        mutated_syntax_map.reparse(language.clone(), &buffer);
2089
2090        for (i, marked_string) in steps.into_iter().enumerate() {
2091            edit_buffer(&mut buffer, &marked_string.unindent());
2092
2093            // Reparse the syntax map
2094            mutated_syntax_map.interpolate(&buffer);
2095            mutated_syntax_map.reparse(language.clone(), &buffer);
2096
2097            // Create a second syntax map from scratch
2098            let mut reference_syntax_map = SyntaxMap::new();
2099            reference_syntax_map.set_language_registry(registry.clone());
2100            reference_syntax_map.reparse(language.clone(), &buffer);
2101
2102            // Compare the mutated syntax map to the new syntax map
2103            let mutated_layers = mutated_syntax_map.layers(&buffer);
2104            let reference_layers = reference_syntax_map.layers(&buffer);
2105            assert_eq!(
2106                mutated_layers.len(),
2107                reference_layers.len(),
2108                "wrong number of layers at step {i}"
2109            );
2110            for (edited_layer, reference_layer) in
2111                mutated_layers.into_iter().zip(reference_layers.into_iter())
2112            {
2113                assert_eq!(
2114                    edited_layer.node.to_sexp(),
2115                    reference_layer.node.to_sexp(),
2116                    "different layer at step {i}"
2117                );
2118                assert_eq!(
2119                    edited_layer.node.range(),
2120                    reference_layer.node.range(),
2121                    "different layer at step {i}"
2122                );
2123            }
2124        }
2125
2126        (buffer, mutated_syntax_map)
2127    }
2128
2129    fn html_lang() -> Language {
2130        Language::new(
2131            LanguageConfig {
2132                name: "HTML".into(),
2133                path_suffixes: vec!["html".to_string()],
2134                ..Default::default()
2135            },
2136            Some(tree_sitter_html::language()),
2137        )
2138        .with_highlights_query(
2139            r#"
2140                (tag_name) @tag
2141                (erroneous_end_tag_name) @tag
2142                (attribute_name) @property
2143            "#,
2144        )
2145        .unwrap()
2146    }
2147
2148    fn ruby_lang() -> Language {
2149        Language::new(
2150            LanguageConfig {
2151                name: "Ruby".into(),
2152                path_suffixes: vec!["rb".to_string()],
2153                ..Default::default()
2154            },
2155            Some(tree_sitter_ruby::language()),
2156        )
2157        .with_highlights_query(
2158            r#"
2159                ["if" "do" "else" "end"] @keyword
2160                (instance_variable) @ivar
2161            "#,
2162        )
2163        .unwrap()
2164    }
2165
2166    fn erb_lang() -> Language {
2167        Language::new(
2168            LanguageConfig {
2169                name: "ERB".into(),
2170                path_suffixes: vec!["erb".to_string()],
2171                ..Default::default()
2172            },
2173            Some(tree_sitter_embedded_template::language()),
2174        )
2175        .with_highlights_query(
2176            r#"
2177                ["<%" "%>"] @keyword
2178            "#,
2179        )
2180        .unwrap()
2181        .with_injection_query(
2182            r#"
2183                ((code) @content
2184                 (#set! "language" "ruby")
2185                 (#set! "combined"))
2186
2187                 ((content) @content
2188                 (#set! "language" "html")
2189                 (#set! "combined"))
2190            "#,
2191        )
2192        .unwrap()
2193    }
2194
2195    fn rust_lang() -> Language {
2196        Language::new(
2197            LanguageConfig {
2198                name: "Rust".into(),
2199                path_suffixes: vec!["rs".to_string()],
2200                ..Default::default()
2201            },
2202            Some(tree_sitter_rust::language()),
2203        )
2204        .with_highlights_query(
2205            r#"
2206                (field_identifier) @field
2207                (struct_expression) @struct
2208            "#,
2209        )
2210        .unwrap()
2211        .with_injection_query(
2212            r#"
2213                (macro_invocation
2214                    (token_tree) @content
2215                    (#set! "language" "rust"))
2216            "#,
2217        )
2218        .unwrap()
2219    }
2220
2221    fn range_for_text(buffer: &Buffer, text: &str) -> Range<usize> {
2222        let start = buffer.as_rope().to_string().find(text).unwrap();
2223        start..start + text.len()
2224    }
2225
2226    fn assert_layers_for_range(
2227        syntax_map: &SyntaxMap,
2228        buffer: &BufferSnapshot,
2229        range: Range<Point>,
2230        expected_layers: &[&str],
2231    ) {
2232        let layers = syntax_map
2233            .layers_for_range(range, &buffer)
2234            .collect::<Vec<_>>();
2235        assert_eq!(
2236            layers.len(),
2237            expected_layers.len(),
2238            "wrong number of layers"
2239        );
2240        for (i, (SyntaxLayerInfo { node, .. }, expected_s_exp)) in
2241            layers.iter().zip(expected_layers.iter()).enumerate()
2242        {
2243            let actual_s_exp = node.to_sexp();
2244            assert!(
2245                string_contains_sequence(
2246                    &actual_s_exp,
2247                    &expected_s_exp.split("...").collect::<Vec<_>>()
2248                ),
2249                "layer {i}:\n\nexpected: {expected_s_exp}\nactual:   {actual_s_exp}",
2250            );
2251        }
2252    }
2253
2254    fn assert_capture_ranges(
2255        syntax_map: &SyntaxMap,
2256        buffer: &BufferSnapshot,
2257        highlight_query_capture_names: &[&str],
2258        marked_string: &str,
2259    ) {
2260        let mut actual_ranges = Vec::<Range<usize>>::new();
2261        let captures = syntax_map.captures(0..buffer.len(), buffer, |grammar| {
2262            grammar.highlights_query.as_ref()
2263        });
2264        let queries = captures
2265            .grammars()
2266            .iter()
2267            .map(|grammar| grammar.highlights_query.as_ref().unwrap())
2268            .collect::<Vec<_>>();
2269        for capture in captures {
2270            let name = &queries[capture.grammar_index].capture_names()[capture.index as usize];
2271            if highlight_query_capture_names.contains(&name.as_str()) {
2272                actual_ranges.push(capture.node.byte_range());
2273            }
2274        }
2275
2276        let (text, expected_ranges) = marked_text_ranges(&marked_string.unindent(), false);
2277        assert_eq!(text, buffer.text());
2278        assert_eq!(actual_ranges, expected_ranges);
2279    }
2280
2281    fn edit_buffer(buffer: &mut Buffer, marked_string: &str) {
2282        let old_text = buffer.text();
2283        let (new_text, mut ranges) = marked_text_ranges(marked_string, false);
2284        if ranges.is_empty() {
2285            ranges.push(0..new_text.len());
2286        }
2287
2288        assert_eq!(
2289            old_text[..ranges[0].start],
2290            new_text[..ranges[0].start],
2291            "invalid edit"
2292        );
2293
2294        let mut delta = 0;
2295        let mut edits = Vec::new();
2296        let mut ranges = ranges.into_iter().peekable();
2297
2298        while let Some(inserted_range) = ranges.next() {
2299            let new_start = inserted_range.start;
2300            let old_start = (new_start as isize - delta) as usize;
2301
2302            let following_text = if let Some(next_range) = ranges.peek() {
2303                &new_text[inserted_range.end..next_range.start]
2304            } else {
2305                &new_text[inserted_range.end..]
2306            };
2307
2308            let inserted_len = inserted_range.len();
2309            let deleted_len = old_text[old_start..]
2310                .find(following_text)
2311                .expect("invalid edit");
2312
2313            let old_range = old_start..old_start + deleted_len;
2314            edits.push((old_range, new_text[inserted_range].to_string()));
2315            delta += inserted_len as isize - deleted_len as isize;
2316        }
2317
2318        assert_eq!(
2319            old_text.len() as isize + delta,
2320            new_text.len() as isize,
2321            "invalid edit"
2322        );
2323
2324        buffer.edit(edits);
2325    }
2326
2327    pub fn string_contains_sequence(text: &str, parts: &[&str]) -> bool {
2328        let mut last_part_end = 0;
2329        for part in parts {
2330            if let Some(start_ix) = text[last_part_end..].find(part) {
2331                last_part_end = start_ix + part.len();
2332            } else {
2333                return false;
2334            }
2335        }
2336        true
2337    }
2338}